ATM and cancer: p53 plays crucial roles in regulating cell cycle, cell apoptosis, and genome stability,[19, 20] and is deeply involved in the TGF‐β signaling pathway for cell‐fate decisions and cellular homeostatic via acting as an essential partner of Smads.[21] Moreover, Smad1 has been documented as an important participant in DNA damage response via involving the Atm‐p53 pathway,[22] and is a culprit for colorectal cancer chemoresistance.[23] These findings underscore the significance of Smad1‐p53 interaction in tumorigenesis and chemoresistance of cancers.